Odor Abatement Device

OAD (Odour Abatement Devices), also know as Odour Control Device or Odour Management Device.  These are Polyethylene inserts with Activated Charcoal filter cartridges. They drop inside standard Hong Kong 600mm Square or split manhole frame (DS 1077 A) to absorb foul gas (H2S) that is released from gravity drainage or Air valves during the operation of sewerage rising mains.

As the foul gas in the chamber builds up, it is forced past the valve and through the cartridge filter, before exiting to Atmosphere out the manhole cover. The replaceable cartridge is filled with a special activated carbon which absorbs the smell associated with H2S gas.

The Mill-Pro OAD is designed with the following features to maximise cartridge life:

  • Rain Guard - to protect the Activated Carbon from being saturated by surface water leaking past the chamber lid.
  • High Pressure bypass valve - vents large quantities of Air (filling the pipeline) to atmosphere so as to not damage the media.
  • Expansion Bag - absorbs pressure changes inside the chamber to reduce media saturation
  • Media protection valve - prevents the activated Charcoal from being continually depleted due to constant gas exposure.  

Without the expansion bellows and the media protection valve the foul gases in the chamber saturate the media in the cartridge after a short period of time and render it ineffective.  These features preserve the absorbent ability of the media providing an typical annual replacement cycle, rather than after just a few months.

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